| 摘要 |
PURPOSE:To vary the ratio of the input X-ray dose to the output image signal level of a television camera by providing a means which switches the conversion efficiency of an image intensifier into the deisred value. CONSTITUTION:The X ray which is irradiated from an X-ray tube 11 and passes through a checked object is received by an image intensifier 12. This image intensifier 12 has a photoelectric cathode 12a. The electron generated from the photoelectric cathode 12a by the X-ray irradiation is forcussed by a focussing electrode 12b, accelerated by an anode 12c, and converted into fluorescent on an out phosphor screen 12d. The voltage with difference values is applied to the focussing electrode 12b and the anode 12c by changeover switches 14 and 17. The fluorescence image from the output phosphor screen 12d is imaged by a television camera 21 through a tandem lens system 20 and the image signal is reproduced by a television monitor 22. |
